CN113194036B - Routing method, system, device and readable storage medium for multi-label network - Google Patents

Abstract

The invention discloses a routing method, a system, equipment and a readable storage medium for a multi-label network.A frame structure that a reader-writer and an electronic label transmit information is adopted to ensure the accuracy of low-power reflected signals during information feedback, excited passive labels carry out mu code encoding on label ID information at different chip rates, the labels of each hop respectively carry out mu code decoding on the received reflected signals, the decoded label ID information and self ID information are reflected to an excitation signal source together, the provided routing scheme is optimized according to the requirements of different application scenes of the multi-hop label network, the long-distance transmission of the passive labels is realized through the multi-hop routing, the throughput of the multi-hop label network is increased, the effectiveness of information transmission is improved, the data information to be transmitted by each label is modulated onto the excitation signals transmitted from the reader-writer, and the passive labels of each hop are ensured to have enough detection energy to carry out decoding and enveloping, so as to realize the reflection of adjacent information.

Description

Routing method, system, device and readable storage medium for multi-label network

technical field

The invention belongs to the technical field of communication, and relates to a routing scheme in a multi-hop label network under the background of backscattering and cooperative information transmission of multi-hop labels, and in particular to a routing method, system, device and method for a multi-label network. readable storage media.

Background technique

Due to the outstanding characteristics of passive electronic tags in RFID technology such as low cost, small size, and long life, after the tag-to-tag communication network (T2T) that electronic tags can communicate with each other was proposed, multi-tag networks have become popular research in RFID systems. one. Due to the power limit of the radio frequency signal, the transmission power of the reader in the FCC specification is 1Watt, and the reflected signal of the passive electronic tag is affected by signal attenuation during the reflection process, so that the signal power reaching the next hop tag is not enough to support The tag is reflective, so tag-to-tag network communication can only achieve reflective communication at centimeter-level distances.

In order to realize long-distance tag communication, there are two ways of forwarding through multi-hop relay tags and forwarding through readers. At present, regarding the routing algorithm of the multi-label network, there is a centralized routing that uses the reader as a relay for information forwarding with a large delay; there is an optimal link cost multipath routing protocol (OLCMR) that uses the modulation depth as the link cost. ), but the label selection path is difficult, and the information interference between labels is serious. How to quickly and accurately find a communication link from a source tag to a destination tag without increasing the complexity of tags is a major challenge in tag-to-tag communication.

Contents of the invention

The object of the present invention is to provide a routing method, system, device and readable storage medium for multi-label network, so as to overcome the deficiencies of the prior art.

To achieve the above object, the present invention adopts the following technical solutions:

A routing method for a multi-label network, comprising the following steps:

S1. Use the excitation signal source to send excitation signals of different powers multiple times, and discover the passive tags of each layer sequentially by layer;

S2. The excited passive tag encodes the tag ID information with μcode at different chip rates, and each hop tag performs μcode decoding on the received reflected signal, and combines the decoded tag ID information with itself The ID information is reflected to the excitation signal source together;

S3. The excitation signal source decodes the received reflection signal and integrates the corresponding adjacency information, generates and stores it as an adjacency information matrix;

S4. Calculate N paths from the source label to the destination label according to the adjacency matrix, and send pilot information to the labels on each path in turn, so that the pilot information is transmitted from the source label to the destination label through a multi-hop relay label;

S5. Decode the received reflected signals in sequence, calculate the bit error rates corresponding to the N paths, and assign the path information with the smallest bit error rate to the multi-label network, so as to obtain a routing scheme from the source label to the destination label.

Further, the source of the excitation signal is a reader.

Further, the excitation signal source discovers tags by layer, and the excited tags are coded with μcode at different chip transmission rates, and reflected to the excitation signal source. After the excitation signal source receives and decodes the ID information of each tag, the ID information of each tag can be obtained. Passive tags included in the network.

Further, the principle of turbo backscattering is used to modulate the data information to be sent by each tag to the excitation signal sent from the reader.

Further, using the depth-first search algorithm, N paths from the source label to the destination label are obtained according to the IDs of the source label and the destination label and the adjacency matrix of the label.

Further, the excitation signal containing pilot information is sent to the source label, and the information is reflected to the excitation signal source through the multi-hop label in the path in turn through the destination label, and the error bits between the decoded and demodulated signal and the pilot signal are calculated The information calculates the bit error rate of the information transmission of the path, and performs cooperative information transmission on the path corresponding to the minimum bit error rate.

Further, send an incentive command to the label on the path corresponding to the minimum bit error rate, and send a silent command to the rest of the labels; the source label performs μcode encoding and ASK modulation on the data information to be transmitted, and reflects it to the next-hop label; The following tags use cooperative network coding technology to XOR process the data information obtained by decoding and demodulation with their own data information, and modulate the information onto the excitation signal for reflection until the target tag is sequentially obtained through cooperative network decoding and μcode decoding. Data information sent by the first K-1 tags.

A routing system for a multi-label network, comprising an excitation signal source unit and a plurality of passive label units annularly distributed around the excitation signal source;

The excitation signal source unit is used to send excitation signals of different powers multiple times, and discover the passive tags of each layer sequentially by layer;

The passive tag unit is used to encode the tag ID information of the received excitation signal at different chip rates in μcode, each hop tag performs μcode decoding on the received reflected signal, and the decoded tag The ID information and its own ID information are reflected to the excitation signal source together;

The excitation signal source unit decodes the received reflection signal and integrates the corresponding adjacency information, generates and stores it as an adjacency information matrix, and calculates the N paths from the source label to the destination label according to the adjacency matrix, and sequentially analyzes each path. The label sends pilot information, so that the pilot information is transmitted from the source label to the destination label through the multi-hop relay label, and finally decodes the received reflected signals in turn, calculates the bit error rate corresponding to the N paths and calculates the bit error rate The minimum path information is assigned to the multi-label network, so as to realize the routing scheme from the source label to the destination label.

A terminal device, comprising a memory, a processor, and a computer program stored in the memory and operable on the processor, when the processor executes the computer program, the above-mentioned routing method for a multi-label network is implemented A step of.

A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned steps of the routing method for a multi-label network are implemented.

Compared with the prior art, the present invention has the following beneficial technical effects:

The present invention is a routing method for a multi-label network. The excitation signal source is used to send excitation signals of different powers multiple times, and the passive labels of each layer are found sequentially by layers. The excited passive labels are transmitted at different chip rates. Perform μcode encoding on the tag ID information, each hop label separately performs μcode decoding on the received reflected signal, and reflects the decoded tag ID information and its own ID information to the excitation signal source together, according to the multi-hop label network According to the needs of different application scenarios, the proposed routing scheme is optimized, and the long-distance transmission of passive tags is realized through multi-hop routing, which increases the throughput of multi-hop tag networks and improves the effectiveness of information transmission.

Furthermore, the frame structure of the information sent by the reader and the electronic tag is adopted to ensure the accuracy of the low-power reflected signal when the information is fed back.

Furthermore, the combination of cooperative network coding and μcode coding not only allows each hop label on the selected path to transmit its own information to the destination label, but also takes into account the interference between the reflected signals of the tags, and uses μcode to encode the correctness of the information. According to the requirements of different application scenarios of multi-hop label networks, the proposed routing scheme is optimized; the long-distance transmission of passive labels is realized through multi-hop routing, which increases the throughput of multi-hop label networks and improves the effectiveness of information transmission.

Using the principle of turbo backscattering, the data information to be sent by each tag is modulated to the excitation signal sent from the reader to ensure that each hop of the passive tag has enough energy for decoding and envelope detection, to achieve Reflection of adjacency information.

Using collaborative network coding technology to reflect its own information can improve the effectiveness of information transmission in the communication system; the specific optimization models of different scenarios are more in line with the requirements of the scenarios and improve the applicability of the routing scheme.

Description of drawings

FIG. 1 is a schematic diagram of the composition of a multi-hop label-based network in an embodiment of the present invention.

FIG. 2 is a flow chart of performing path search in a routing scheme in an embodiment of the present invention.

Fig. 3 is a schematic diagram of a frame structure in an embodiment of the present invention, 3 (a) is a schematic diagram of an excitation signal that a reader/writer sends to a label in its coverage area containing a pilot; Fig. 3 (b) is a schematic diagram of information reflection performed by a data frame structure; Fig. 3(c) is a schematic diagram of performing XOR processing reflection on data information and its own data information.

FIG. 4 is a diagram of path selection simulation results in an embodiment of the present invention.

FIG. 5 is a diagram for verifying the performance of collaborative network coding in an embodiment of the present invention.

FIG. 6 is a diagram for verifying the necessity of routing scheme optimization in an embodiment of the present invention.

Fig. 7 is the simulation result diagram of routing scheme optimization scene 1 in the embodiment of the present invention, and Fig. 7 (a) is the delay simulation result diagram brought by routing scheme optimization scene 1 information transmission; Fig. 7 (b) is routing scheme optimization Scenario 1 screens out the path diagrams that meet the conditions.

Fig. 8 is the simulation result figure of routing scheme optimization scene 2 in the embodiment of the present invention, and Fig. 8 (a) is the routing scheme optimization scene 2 and selects the qualified path schematic diagram; Fig. 8 (b) is routing scheme optimization scene 2 information transmission The resulting delay simulation results.

detailed description

The present invention is described in further detail below in conjunction with accompanying drawing:

A routing method for a multi-label network, the multi-label network includes an excitation signal source and a plurality of ring-shaped passive tags distributed around the excitation signal source, comprising the following steps:

S1. Use the excitation signal source to send excitation signals of different powers multiple times, and discover the passive tags of each layer sequentially by layer;

The excitation signal source adopts the reader-writer, and this application adopts the frame structure of the reader-writer and the electronic tag to send information, which ensures the accuracy of the low-power reflected signal in the information feedback.

S2. The excited passive tag encodes the tag ID information with μcode at different chip rates, and each hop tag performs μcode decoding on the received reflected signal, and combines the decoded tag ID information with itself The ID information is reflected to the excitation signal source together;

S3. The excitation signal source decodes the received reflection signal and integrates the corresponding adjacency information, generates and stores it as an adjacency information matrix;

S4. The excitation signal source calculates N paths from the source label to the destination label according to the adjacency matrix, and sends pilot information to the labels on each path in turn, so that the pilot information is transmitted from the source label to the destination through a multi-hop relay label Label;

S5. The reader decodes the received reflected signals in turn, calculates the bit error rates corresponding to the N paths and distributes the path information with the smallest bit error rate to the multi-label network, so as to realize the routing scheme from the source label to the destination label .

In the present invention, the reader is used as the central controller to send the selected optimal path information to the electronic tags within its range, and stimulate the tags on the selected path to realize the cooperative transmission of multi-hop tag information. Combining cooperative network coding and μcode coding, not only allows each hop label on the selected path to transmit its own information to the destination label, but also considers the interference between tag reflection signals, and utilizes the orthogonality of information encoded by μcode to Reduce distractions. According to the requirements of different application scenarios of multi-hop label network, the proposed routing scheme is optimized. The long-distance transmission of passive tags is realized through multi-hop routing, which increases the throughput of multi-hop tag networks and improves the effectiveness of information transmission.

The excitation signal source adopts the reader-writer, and the reader-writer discovers the tags by layer. The excited tags are encoded with μcode at the transmission rate of different chips, and reflected to the reader-writer. When the reader-writer receives and decodes the ID information of each tag After that, the passive tags contained in the network can be known.

Using the principle of turbo backscattering, the data information to be sent by each tag is modulated to the excitation signal sent from the reader to ensure that each hop of the passive tag has enough energy for decoding and envelope detection, to achieve Reflection of adjacency information. Using the depth-first search algorithm, according to the ID of the source label and the destination label and the adjacency matrix of the label, N paths from the source label to the destination label are obtained.

The reader sends an excitation signal containing pilot information to the source tag, and then passes through the multi-hop tags in the path to reflect the information to the reader through the destination tag, and the reader calculates the decoded demodulated signal and the pilot signal The error bit information of the path is calculated to calculate the bit error rate of the path information transmission, and the path corresponding to the minimum bit error rate is selected for cooperative information transmission; the path corresponding to the minimum bit error rate is the optimal path.

The reader sends an incentive command to the tag on the optimal path, and sends a silent command to the rest of the tags; the source tag performs μcode encoding and ASK modulation on the data information to be transmitted, and reflects it to the next hop tag; the multi-hop relay tag utilizes the cooperative network Coding technology, the data information obtained by decoding and demodulation is XOR-processed with its own data information, and the information is modulated onto the excitation signal for reflection until the target label obtains the first K-1 in sequence through collaborative network decoding and μcode decoding Data information sent by the tag.

The present invention provides an embodiment, a routing system for a multi-label network, including an excitation signal source unit and a plurality of passive label units annularly distributed around the excitation signal source;

The excitation signal source unit is used to send excitation signals of different powers multiple times, and discover the passive tags of each layer sequentially by layer;

The passive tag unit is used to encode the tag ID information of the received excitation signal at different chip rates in μcode, each hop tag performs μcode decoding on the received reflected signal, and the decoded tag The ID information and its own ID information are reflected to the excitation signal source together;

The excitation signal source unit decodes the received reflection signal and integrates the corresponding adjacency information, generates and stores it as an adjacency information matrix, and calculates the N paths from the source label to the destination label according to the adjacency matrix, and sequentially analyzes each path. The label sends pilot information, so that the pilot information is transmitted from the source label to the destination label through the multi-hop relay label, and finally decodes the received reflected signals in turn, calculates the bit error rate corresponding to the N paths and calculates the bit error rate The minimum path information is assigned to the multi-label network, so as to realize the routing scheme from the source label to the destination label.

An embodiment provides a terminal device, the terminal device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium . The processor adopts a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or Transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions to realize the corresponding method flow or corresponding functions; The processor described in the embodiment of the invention can be used for the operation of the routing method of the multi-label network.

In yet another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a terminal device for storing programs and data. . The computer-readable storage medium includes a built-in storage medium in the terminal device, which provides storage space and stores the operating system of the terminal, and may also include an extended storage medium supported by the terminal device. Moreover, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions may be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here may be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as at least one magnetic disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor, so as to implement the corresponding steps of the routing method related to the multi-label network in the above-mentioned embodiments.

Take a network of ten passive tags distributed over two layers as an example. As shown in Figure 1, the network consists of a reader at the center and dozens of electronic tags distributed in a layered ring; here, each tag is set to unidirectionally reflect signals in the direction of the arrow shown in Figure 1, and each The reflection coefficient λ _k of each tag is determined by itself. The reader sends excitation signals of different powers to excite the electronic tags on each layer separately, and the excited electronic tags encode the tag ID information with μcode at different chip rates. Let the source tag be T1 and the destination tag be T10. Tag T1 encodes its own ID information and reflects the information. The reader and tag T2 will receive the reflected signal and decode the μcode. After decoding the ID information of tag T1, tag T2 will decode the ID information of tag T1 and tag T2 The ID information is reflected to the reader. At this time, the reader knows that there is a link between the tag T1 and the tag T2 according to the decoded information, and can communicate. By analogy, until each tag feeds back its adjacency information to the reader, the reader integrates the adjacency information of the multi-hop tag network, obtains the corresponding adjacency information table, and converts it into an adjacency matrix for storage.

During the path search process, the reader searches for 4 paths from the source tag T1 to the destination tag T10 according to the depth-first search algorithm shown in Figure 2, and the reader sends a pilot message to the tags in its coverage area. The excitation signal (as shown in Figure 3(a)) stimulates the tags on each path in turn. When all tags receive and demodulate the signal sent by the reader, they compare the ID information with their own ID. When When the ID information of the transmitted signal contains its own ID information, the tag is activated, and when there is no self-ID information, the tag is silenced.

After the source tag is excited by the reader, the pilot information is obtained through envelope detection, and then ASK modulation is performed on the pilot information, and the ID information of the source tag and the calculated CRC check code are modulated onto the excitation signal, and reflected to the next One hop label, the relay label node demodulates the received reflected signal of the previous label, and modulates its own ID information and the demodulated information onto the carrier wave, as shown in Figure 3(b) The data frame structure performs information reflection until the target tag demodulates the reflected signal of the previous hop tag, modulates the demodulated pilot information and tag ID information, and then reflects them to the reader. Demodulate the signal and compare it with the initial pilot information to calculate the bit error rate of the path. After the reader has traversed all the existing paths, compare the calculated N bit error rates and select the bit error rate The path with the smallest rate is used as the optimal path for the information transmission from the source label to the destination label in the multi-hop label network.

Figure 4 shows the BER curves of the four paths when the label reflection coefficient matrix is Λ=[0.9,0.7,0.9,0.8,0.9,0.8,0.7,0.7,0.6,0.7], although each path The bit error rate of each path decreases with the increase of the signal-to-noise ratio, but the bit error rate of the first path is always lower than that of other paths, so the reader activates the tag on the first path and Carry out collaborative information transmission.

The reader sends incentive commands to the tags on the optimal path, and sends silent commands to the rest of the tags. The source label performs μcode encoding and ASK modulation on the data information to be transmitted, and reflects it to the next-hop label. The relay label uses cooperative coding technology to perform exclusive-or processing on the data information obtained by decoding and demodulation and its own data information, and performs the processing according to the figure The structure shown in 3(c) is reflected until the destination tag decodes in turn to obtain the data information sent by the first K-1 tags.

Figure 5 shows the comparison results of the throughput of tags on the selected path using cooperative network coding technology for information transmission and not using this technology. The throughput is increased by about 50%.

Figure 6 shows the change curves of the three parameters of bit error rate, power consumption and delay corresponding to the 14 paths from the source label to the destination label when the signal-to-noise ratio is 8dB, which proves that the three parameters cannot simultaneously meet the optimal requirements. Therefore, it is necessary to optimize according to the needs of different scenarios.

In the scenario of smart logistics, each package is affixed with an electronic label, and the label stores the corresponding package information. In order to facilitate the long-distance package to send the information to the transshipment center earlier, the label on the far package and the distance The package label near the transshipment center communicates to achieve the purpose of updating information early and starting logistics preparation work early. In this scenario, in addition to the accuracy of package information transmission, the time delay caused by information transmission must also be considered, and Based on the power loss during multi-hop intermediate package forwarding, a corresponding optimization model is designed, as shown in formula (1).

D(P) _≤Dmax

stE(P) _≤Emax

0≤λk≤1, for _k =1,...,n (1)

The performance simulation results of the optimization model 1 designed by the present invention are shown in Figure 7, the maximum acceptable time delay _Dmax is set to 0.5s, and the maximum acceptable power consumption _Emax is 0.3W. Paths are paths 3, 11, and 15, and then compare the bit error rate. According to the results, the optimal path selected at this time is the 15th path, which greatly reduces the time complexity of the routing scheme.

In smart home application scenarios, electronic tags are attached to home appliances to realize information interaction. More often, information interaction occurs when there is no one at home. Therefore, when the information transmission delay and accuracy are within an acceptable range , focusing on power loss, the optimization model established according to this scenario is shown in formula (2).

D(P) _≤Dmax

stBER(P) _≤Bmax

0≤λk≤1, for _k =1,...,n (2)

The performance simulation results of the optimization model 2 designed by the present invention are shown in Figure 8, wherein the maximum time delay _Dmax is 0.5s, the acceptable maximum bit error rate _Bmax is 0.025, and when the signal-to-noise ratio is 5dB, the conditional There are only 4 paths, and the path with the least power consumption is the seventh path.

Claims (10)

1. A routing method for a multi-label network, comprising the steps of:

s1, sending excitation signals with different powers for multiple times by using an excitation signal source, and sequentially discovering passive tags of each layer according to layers;

s2, carrying out mu code encoding on the ID information of the excited passive tag at different chip rates, respectively carrying out mu code decoding on the received reflected signal by each hop of tag, and reflecting the decoded ID information of the tag and the ID information of the tag to an excitation signal source;

s3, the excitation signal source decodes the received reflected signals and integrates corresponding adjacent information to generate and store an adjacent information matrix;

s4, calculating N paths from the source label to the target label according to the adjacent information matrix, and sending pilot frequency information to the labels on each path in sequence to enable the pilot frequency information to be transmitted from the source label to the target label through the multi-hop relay label;

and S5, decoding the received reflected signals in sequence, calculating the error rates corresponding to the N paths, and distributing the path information with the minimum error rate to the multi-label network, thereby obtaining a routing scheme from the source label to the target label.

2. The routing method for the multi-label network according to claim 1, wherein the excitation signal source is a reader.

3. The routing method for multi-tag network according to claim 1, wherein the excitation signal source finds the tags by layers, the excited tags are μ -code encoded with different chip transmission rates and reflected to the excitation signal source, and the passive tags included in the network are obtained when the excitation signal source receives and decodes the ID information of each tag.

4. The routing method for multi-tag network according to claim 1, wherein the data information to be transmitted by each tag is modulated onto the excitation signal transmitted from the reader/writer by using turbo backscattering principle.

5. The routing method for the multi-label network according to claim 1, wherein the N paths existing from the source label to the destination label are obtained according to the IDs of the source label and the destination label and the adjacency information matrix of the labels by using a depth-first search algorithm.

6. The routing method for the multi-tag network according to claim 1, wherein an excitation signal containing pilot information is sent to a source tag, information is reflected to an excitation signal source through a destination tag sequentially via a multi-hop tag in a path, the error rate of information transmission of the path is calculated by calculating error bit information of the decoded and demodulated signal and the pilot signal, and cooperative information transmission is performed on a path corresponding to the minimum error rate.

7. The routing method for the multi-label network according to claim 6, wherein the excitation instruction is sent to the label on the path corresponding to the minimum bit error rate, and the silence instruction is sent to the rest labels; carrying out mu code encoding and ASK modulation on data information to be transmitted by a source tag, and reflecting the data information to a next hop tag; the multi-hop relay tag performs XOR processing on data information obtained by decoding and demodulating and data information of the multi-hop relay tag by utilizing a cooperative network coding technology, modulates the information onto an excitation signal to be reflected until a target tag sequentially obtains the data information sent by the first K-1 tags through cooperative network decoding and mu code decoding.

8. A routing system for a multi-label network is characterized by comprising an excitation signal source unit and a plurality of passive label units which are annularly distributed around the excitation signal source;

the excitation signal source unit is used for sending excitation signals with different powers for multiple times and sequentially finding passive tags of each layer according to the layers;

the passive tag unit is used for carrying out mu code encoding on tag ID information of the received excitation signal at different chip rates, carrying out mu code decoding on the received reflection signal by each hop of tag, and reflecting the decoded tag ID information and the ID information to an excitation signal source;

the method comprises the steps that an excitation signal source unit decodes received reflection signals and integrates corresponding adjacent information to generate and store an adjacent information matrix, N paths from a source label to a target label are calculated according to the adjacent information matrix, pilot frequency information is sent to labels on each path in sequence to enable the pilot frequency information to be transmitted to the target label from the source label through a multi-hop relay label, finally the received reflection signals are decoded in sequence, the error rates corresponding to the N paths are calculated, and the path information with the minimum error rate is distributed to a multi-label network, so that a routing scheme from the source label to the target label is achieved.

9. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the steps of the method of any of claims 1 to 7 are implemented when the computer program is executed by the processor.

10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.

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